Pyrite Morphology Variations from the Upper Cretaceous Qingshankou Formation Unit 1 in Songliao Basin,Northeast China:Evidence for Excursions of the O2-H2S Redox Transition

Pyrite is a ubiquitous authigenic mineral in modern anoxic sediments and occurs in ancient sedimentary rocks.Study of sedimentary pyrite morphology, which can provide useful information on deposition environments and early diagenetic processes,has become an important aspect for reconstruction of palaeoenviroment.The Upper Cretaceous Qingshankou Formation Unit 1（K2qn1）lithology,which occured in the south well of the SLCORE I for Continental Cretaceous Scientific Drilling Project